Piezoelectric Power Generator With Non-Uniform Support Body
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Solution Overview
Problem
Piezoelectric power generation devices face issues with stress concentration leading to breakage and reduced power generation efficiency due to high spring constants and centralized pressure distribution, making them prone to mechanical failure and inefficient energy conversion.
Innovation Solution
The design incorporates overlapping power generation elements with support bodies featuring projecting portions and leg portions that distribute stress uniformly, reducing the load on piezoelectric bodies and enhancing deformation curvature, thereby increasing mechanical strength and power generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the doughnut-like outer circumferential portions of the elastic bodies are made to abut against each other, then the spring constant is increased, but a large load is necessary for deforming the piezoelectric elements and power generation efficiency is reduced
Solution Approach 1:
The support body is designed with non-uniform thickness, being thicker at the center portion and thinner at the peripheral edge portion. This local quality variation allows the center to provide strong support (high spring constant) while the thinner peripheral edges allow easier deformation (lower overall spring constant), resolving the contradiction between strength and power generation efficiency.
Solution Approach 2:
The support body is divided into distinct regions with different thicknesses - a center portion and a peripheral edge portion. This segmentation allows each region to perform its specific function: the thicker center provides structural strength while the thinner peripheral regions facilitate deformation under load, enabling both high spring constant and good power generation efficiency.
2Productivity
If pressure members with convex lens-like shapes are used, then the piezoelectric elements can be deformed, but stress is concentrated at the center point and the piezoelectric elements are prone to breakage
Solution Approach 1:
The support body has different thicknesses at different locations - thicker at the center and thinner at the periphery. This local quality distribution moderates stress concentration by providing gradual thickness transition, reducing the risk of piezoelectric element breakage while still enabling effective deformation for power generation.
Solution Approach 2:
The varied thickness design of the support body acts as a pre-designed stress distribution mechanism that cushions against stress concentration before it can cause damage. The thicker central region absorbs and distributes the applied load, preventing excessive stress from reaching the piezoelectric elements at the center point.
3Device complexity
If the central spacer is adhered to the center point of the piezoelectric elements, then the structure is simplified, but pressure is concentrated on the center point and braking risk is higher
Solution Approach 1:
The support body incorporates local quality variation through non-uniform thickness distribution. The thicker center portion and thinner peripheral edges create a natural stress distribution pattern that prevents pressure concentration at the center point, reducing braking risk without requiring complex additional structures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively moderates stress concentration, increases the mechanical strength of piezoelectric bodies, and enhances power generation efficiency by distributing pressure uniformly across the elements, making them less prone to breakage and improving energy conversion.
Implementation Method 1
a piezoelectric body provided on the one main surface of the planar portion
Data Source
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AI summary
Provided is a piezoelectric power generation device that has high power generation efficiency and makes a piezoelectric body hard to be broken. A piezoelectric power generation device 21 includes a plurality of power generation elements 22 each of which has a support body 3A configured by a plate-like planar portion having one main surface 3Aa and the other main surface 3Ab and a projecting portion 3Ad projecting from a center portion of the other main surface 3Ab, and a piezoelectric body 4A provided on the one main surface 3Aa, and is arranged such that the piezoelectric body 4A overlaps with the projecting portion when the support body 3A is seen in plan view along a direction perpendicular to the one main surface 3Aa, wherein the plurality of power generation elements 22 overlap with each other in the direction perpendicular to the one main surface 3Aa, the support body 3A in at least one of a pair of adjacent power generation elements 22 includes a plurality of support portions (leg portions) 3Ac projecting from a peripheral edge portion of the planar portion, which is located in an outer side portion relative to the center portion, and the plurality of power generation elements overlap with each other with the leg portions 3Ac interposed therebetween such that the other main surface 3Ab and the one main surface 3Aa of the support bodies 3A of the pair of adjacent power generation elements 22 oppose each other.